Do we know the last time that someone saw her? If she worked on Monday, she must have been killed in her home some time after work. I'm trying to put myself in the guy's shoes for a moment to figure out how much time he had and how he might have used that time. This may lead to some knowledge of what happened to her.
He was spotted at a store buying cleaning supplies on Monday.
He contacts police late Tuesday evening.
It's worth noting that the carpets weren't dry. So I'm thinking he spent a good part of Tuesday cleaning the house.
He says she left Tuesday morning. That is a lie, of course. But he has to know that a neighbor might have seen her car at home on Monday night. So he can't say she never came home. And he also knows that a neighbor might have seen the car leave the house. So that time he gives for when his wife left is most certainly the time he left in the car.
So, he leaves early Tuesday morning with the car and leaves it close enough that he can walk home before daylight. He gets home. Now it's cleaning time. Clearly, it was an all-day job that was never quite finished.
My guess is that he used every minute he had available. If he waits until late in the evening to leave the house, he still probably has 4-5 hours to dispose of the body. That's a possible two-hour drive. So, where does one go when one is educated and is trying to get rid of a body? Rivers are always a possibility. There are tons of lakes not far away in the Ozarks area. Certainly, he had opportunity to put a lot of distance between himself and his deceased wife. I hope they find her soon. For her family's sake and to make sure that he gets the maximum possible sentence.
Now, about this co-worker thinking that it might have been a domestic issue. Did she speak of violence at home before? Was someone she worked with in a relationship with her? I guess we'll have to wait and see how it plays out.